The invention relates to the treatment of Human Immunodeficiency Virus (HIV) infection and other infections.
HIV infection leads to progressive deterioration of the immune system in most infected subjects. This infection frequently leads to an immune system dysfunction which may culminate in AIDS, a syndrome characterized by the development of opportunistic infections and cancer (Levy, 1993, Microbiol. Rev., 57:183-289). Cells infected with HIV include, e.g., CD4+ T cells, macrophages/monocytes, dendritic cells, and glial cells. The immune system in late stages of AIDS is severely compromised due to loss or dysfunction of CD4+ T cells (Shearer et al., 1991, AIDS, 5:245-53), macrophages, monocytes and dendritic cells. (Rosenberg et al., 1989, Adv. Immunol., 46:377).
Anti-retroviral drugs, such as reverse transcriptase inhibitors, viral protease inhibitors, and viral entry inhibitors have been used to treat HIV infection. (Caliendo et al., 1994, Clin. Infect. Dis., 18:516-24). These treatments can effectively suppress viral production when used in combinations known as HAART (highly active anti-retroviral therapy). However, they are mainly effective in preventing new infection of uninfected cells. They are generally far less effective in eliminating latent virus from infected cells. Even after two years on HAART, HIV-1 can still be induced, and viral production resume when HAART is stopped (Finzi et al., 1997, Science, 278:1295-1300; Wong et al., 1997, Science, 278:1291-1295). Hence, HAART likely needs to be continued indefinitely. This poses significant difficulties. HAART regimens have many side effects, are difficult to comply with, and are expensive. Moreover, prolonged treatment with these drugs often leads to the emergence of drug resistant viral strains (Larder et al., 1989, Science, 246:1155-8; Kellam et al., 1992, Proc. Nat""l. Acad. Sci. USA, 89:1934-8; St. Clair et al., 1991, Science, 253:1557-9). Combination therapies entailing treatment with two or more drugs which attack different points in the HIV replication cycle delay the emergence of resistant HIV strains. (D""Aquila, 1994, Clin. Lab. Med., 14:393:422). However, recent data suggest that HIV strains having multi-drug resistance may eventually develop in a significant portion of patients treated with combination therapy. (Schinazi et al., 1994, Int. Antiviral News, 2:72-5).
Many other important infectious pathogens can exist in a latent state where they are dormant or replicate very slowly. Examples of these pathogens include retroviruses, e.g., human immunodeficiency virus type 2 (HIV-2), human T lymphotropic virus type 2 (HTLV-2); herpesviruses, e.g., Epstein-Barr virus (EBV), cytomegalovirus (CMV), herpes simplex type 1 (HSV-1), herpes simplex type 2 (HSV-2), herpes zoster virus (HZV), herpes virus type 6 (HHV-6), herpes virus type 7 (HHV-7); hepatitis viruses, e.g., hepatitis B (HBV), hepatitis C (HCV), the delta agent, and hepatitis E, mycobacteria, e.g., M. tuberculosis (MTB), M. avium (MA), M. Leprae; and fungal agents e.g., histoplasmosis, coccidiomycosis, cryptococcus, and pneumocystis. Keeping the infectious pathogen in latency is desirable when there is no available therapy. However, in many cases, the pathogen is not completely latent and therapy is required. Unfortunately, while active infection can often be contained by therapy, it is difficult or impossible to attack latent pathogen. Moreover, latent infection can give rise to renewed production of the infectious microbes when the anti-viral/anti-microbial agents are stopped.
HIV-2 can cause immunodeficiency similar to HIV-1. HTLV-1 has been shown to cause T cell lymphoma. EBV may cause lymphoma and other lymphoproliferative diseases. CMV may cause retinitis, hepatitis, pneumonitis, and other systemic illness, especially in immunocompromised host. HSV 1 and 2, and Herpes Zoster (HZV) can cause painful vesicles at the area of infection and occasional meningitis. HHV-6 has been demonstrated to be present in and may contribute to the pathogenesis in certain subgroups of patients with multiple sclerosis and chronic fatigue syndrome. Nucleoside analogs such as ganiclovir, famciclovir, lamivudine, and ribavirin have been shown to be effective against many of these infections. These drugs interfere with viral replication, but they generally cannot attack latent virus. Hence, viral replication often resumes when the drugs are withdrawn.
The invention features a method for treating HIV infection and other infections. The method entails the administration of: (1) a substance which induces active pathogen replication in a cell latently infected with the pathogen and (2) an anti-pathogen drug.
In a preferred embodiment the invention features a method for treating retroviral, e.g., HIV-1 infection, by administering: (1) a substance which induces active viral replication in a latently infected cell and (2) an anti-retroviral drug.
The substance used to induce active viral replication is generally a substance which induces the activation or proliferation of the latently infected cell, e.g., a T cell, or is substance capable of inducing viral replication. Mitogenic lectins, such as phytohemagglutinins, can induce the activation or proliferation of human T cells. Similarly, polyclonal or monoclonal antibodies capable of binding T cell surface molecules such as, e.g., xcex1, xcex2 or xcex3, 67  T cell receptors, CD3, CD2, CD4, CD8, CD28, Thy-1, can often induce T cell activation or proliferation. Additionally, bispecific monoclonal antibodies capable of binding more than one antigen can be used. For example, a bispecific monoclonal antibody (BSMAB) having specificity for both CD3 and CD8, (CD3, 8 BSMAB) can induce activation and proliferation of CD4+ T cells. (Wong et al., 1987, J. Immunol., 139:1369-74; Wong et al., 1989, J. Immunol. 143:3403-11, U.S. Pat. No. 5,601,819, all incorporated herein by reference).
Substances that can activate viral replication directly include: cytokines such as TNF-xcex1 and other stimulators of NFxcexaB activity, analogs or fragments of cytokines such as IL-1 and IL-2 and IL-7, and transactivators encoded by various sequences from various virus, e.g., herpes virus (HSV, EBV, CMV, HHV-6), HTLV-1, and HBV.
The anti-retroviral drug used in the methods of the invention can be any substance which can inhibit, reduce or eliminate retroviral infection of a cell. Commonly used anti-retroviral drugs include reverse transcriptase inhibitors, protease inhibitors, and inhibitors of viral entry. Reverse transcriptase inhibitors can be nucleoside analogues, e.g., AZT (Zidovudine; Glaxo-Burroughs Wellcome Co., Research Triangle Park, N.C.), ddI (Didanosine; Bristol-Myers Squibb; Wallingford, Conn.), 3TC (Glaxo-Burroughs Wellcome), d4T (Stavudine; Bristol-Myers Squibb), or ddC (Zalcitabine; Hoffman-La Roche; Basel, Switzerland); or non-nucleoside drugs, e.g., Nevirapine (Viramune; Roxane Laboratories; Columbus, Ohio), Delaviridine (Rescriptor; Pharmacia and Upjohn; Kalamazoo, Mich.), Abacavir or Pyridnone (Merck, Sharp and Dohme; Rahway, N.J.). Protease inhibitors which can be used include, e.g., Indinavir (Crixivan; Merck; West Point, Pa.), Ritonavir (Novir; Abbott Laboratories; Abbott Park, Ill.), Saquinavir (Invirase; Roche; Palo Alto, Calif.), Nelfinavir (Agouron Pharmaceuticals; La Jolla, Calif.), and Amprenavir.
The invention also features a method of treating a patient infected with HIV, comprising administering to the patient either (a) an amount of a CD4+ T cell mitogen sufficient to induce activation of CD4+ T cells and replication of HIV within latently infected CD4+ T cells in combination with a therapeutically effective amount of at least one, but preferably more than one, anti-retroviral drug, (b) or a direct virus activator in combination with a therapeutically effective amount of at least one, but preferably more than one, anti-retroviral drug.
The invention also features an ex vivo method of expanding CD4+ T cells from a sample of peripheral blood mononuclear cells (PBMCs) isolated from a human. CD4+ T cells are expanded by culturing PBMCs in an artificial capillary cell culture system in the presence of an amount of a CD4+ T cell mitogen, e.g., CD3, 8 BSMAB sufficient to induce activation of CD4+ T cells and replication of HIV within latently infected CD4+ T cells. The invention also features an ex vivo method of expanding CD4+ T cells from a sample of peripheral blood mononuclear cells isolated from a human, comprising culturing the peripheral blood mononuclear cells in an artificial capillary cell culture system in the presence of a T cell mitogen and at least one anti-retroviral drug.
The invention also features a method of treating an HIV-infected patient by administering to the patient the CD4+ cells grown ex vivo. By the methods described above, CD4+ T cells taken from the patient can be expanded ex vivo to sufficient quantity to transfuse back into the patient.
The invention also features a method of treating a patient infected with HTLV, comprising administering to the patient an amount of either (a) a CD4+ T cell mitogen sufficient to induce activation of CD4+ T cells and replication of HTLV within latently infected CD4+ T cells and a therapeutically effective amount of at least one, but preferably more than one, anti-retroviral drug or (b) a direct virus activator and with a therapeutically effective amount of at least one, but preferably more than one, anti-retroviral drug. Anti-retroviral drugs can include reverse transcriptase inhibitors, viral protease inhibitors, and viral entry inhibitors (e.g., fragments of viral entry receptors or co-receptors).
The invention also features a method of treating a patient infected with members of the herpesvirus family such as EBV, CMX, HSV type 1, HSV type 2, HHV-6 and HHV-7, comprising administering to the patient an amount of either (a) a cellular mitogen sufficient to induce activation of the latently infected cells and replication of the virus within the infected cells and therapeutically effective amount of at least one, but preferably more than one, antiviral drug or (b) a direct virus activator and a therapeutically effective amount of at least one, but preferably more than one, anti-viral drug. The cellular mitogen may include PHA for all cell types, pokeweed mitogen for B cells (EBV), LPS (lipopolysaccharide) for monocytes/macrophages, anti-CD3/TCR for T cells. Viral activators, some of which may be cellular activators, include IL-6, TNF-xcex1, and GM-CSF. Anti-viral drugs effective against the herpesvirus family include Acyclovir (Glaxo Wellcome), Ganiciclovir (Roche Laboratories), and Famciclovir (SmithKline Beecham).
The invention also features a method of treating a patient infected with a hepatitis virus that causes chronic diseases such as hepatitis B, hepatitis C, delta agent, and hepatitis E, comprising administering to the patient an amount of either: (a) a cellular mitogen sufficient to induce activation of the latently infected cells and replication of the virus within the infected cells and therapeutically effective amount of at least one, but preferably more than one, anti-viral drug, or (b) a direct virus activator and a therapeutically effective amount of at least one, but preferably more than one, anti-viral drug. The cellular mitogens include PHA for all cell types, LPS (liposaccharide) for monocytes/macrophages, and anti-CD3/TCR for T cells. Viral activators, some of which may be cellular activators, include IL-6, IFN-xcex3, and TNF-xcex1. Anti-viral drugs affective against the hepatitis viruses include: Lamivudine (Glaxo Wellcome), Ganciclovir (Roche Laboratories), Faciclovir (SmithKline Beecham), and IFN-xcex1, (SmithKline Beecham).
The invention also features a method of treating a patient infected with a pathogen that has a latent state, e.g., infection with a mycobacteria, the method comprising administering to the patient either (a) an amount of cellular mitogen sufficient to induce activation of the latently infected cells and replication of the infectious pathogen and a therapeutically effective amount of at least one, but preferably more than one, anti-infection drug or (b) a direct activator of the infectious pathogen and a therapeutically effective amount of at least one, but preferably more than one, anti-infection drug. Suitable cellular mitogens include: PHA for all cell types, LPS (liposaccharide) for monocytes/macrophages, and anti-CD3/TCR for T cells. Activators include corticosteroid, TNF-xcex1, and IL-2. In some cases, activators of the microorganism may also act as cellular activators. Drugs which may be used to treat mycobacterial infection include isoniazid, rifampin, clarithromycin, and ethambutol.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In the case of conflict, the present document, including definitions, will control. Unless otherwise indicated, materials, methods, and examples described herein are illustrative only and not intended to be limiting.
Various features of the invention will be apparent from the following detailed description and from the claims.